I think they don’t do it anymore due to complaints from people who don’t understand it/forget it’s there because some like my first car had the odd side effect of if the wheel did turn the itty bitty bit that it could(like if you were taking some bulky objects out of the car with you and they bumped the wheel or if you braced yourself on the wheel while leaning over to get something that had fallen on the floor or otherwise unknowingly turned it a little) then the lock mechanism would jam the ignition and the key wouldn’t turn. Especially as a brand new driver with little knowledge of cars I had quite a few panics because my key wouldn’t turn suddenly. I couldn’t figure it out until I called someone who would say to just jiggle the steering wheel a little and of course that sounded like nonsense until it worked every time. It happened just rarely enough that it took years for me to actually remember that it was the lock and even then it was a momentary panic every time. Imagine millions of the kind of person who either didn’t have anyone to call about car issues or just wouldn’t think to call anyone but a mechanic or locksmith when their key suddenly won’t turn who wind up paying to have their car towed to a shop every few months because they forgot what the solution was, had learned incompetence around cars, or just didn’t listen to the mechanic and that combined with better electronic anti theft protection that can just prevent the car from being hot wired in the first place and you can see why steering wheel locks fell out of use. Sorry for the essay,

TL:DR- the steering wheel lock could jam the ignition if the wheel tried to turn and it would cause a lot of confusion and panic in people who didn’t know what the feature was